Starbursts around lights, particularly at night, are a common visual phenomenon. They appear as streaks, rays, or spikes emanating from a light source. This article explores the underlying reasons why people perceive these starburst patterns.
Understanding the Visual Phenomenon
Starbursts occur due to how light interacts with the eye’s internal structures. Light passes through the cornea and lens, which focus it onto the retina. If there are irregularities in these structures, light can scatter or diffract instead of focusing precisely. This scattering creates the elongated rays or spikes seen as starbursts.
Light diffraction can cause lines radiating from bright sources, leading to the starburst effect. This phenomenon can be influenced by elements such as eyelashes or the edges of eyelids, especially when squinting. The irregular bending of light results in this form of light distortion.
Common Causes of Starburst Vision
A frequent cause of starburst vision is refractive errors, such as astigmatism. This occurs when the cornea or lens has an irregular, egg-like shape rather than a perfectly round one. This uneven curvature causes light to scatter, preventing a single, sharp focal point on the retina and creating starburst patterns.
Dry eyes can also contribute to starbursts. An uneven or insufficient tear film on the eye’s surface creates an irregular optical surface. This irregularity causes light to scatter as it enters the eye, leading to perceived starbursts or glare.
Individuals who have undergone eye surgeries, such as LASIK or cataract surgery, may experience starbursts. LASIK alters the cornea’s shape, affecting how light is focused and sometimes resulting in starbursts. Following cataract surgery, where the natural cloudy lens is replaced, some patients might notice starbursts due to the new lens or residual corneal changes.
Medical Conditions Associated with Starbursts
Starbursts can also be a symptom of more significant medical conditions. Cataracts, the clouding of the eye’s natural lens, are a common age-related condition that can lead to starburst vision. The cloudy lens scatters light, causing lights to appear with radiating patterns and often accompanied by hazy vision or light sensitivity.
Fuchs’ dystrophy is a corneal condition that may present with starbursts. This disorder affects the innermost layer of the cornea, causing fluid to build up and the cornea to swell, leading to blurred or hazy vision that can worsen throughout the day. The corneal swelling and irregularities can distort incoming light, producing starbursts or halos.
Starbursts can sometimes be an early indicator of glaucoma, a condition characterized by optic nerve damage, often due to elevated fluid pressure. While not a primary symptom, changes in vision or light perception can sometimes occur. Glaucoma typically causes gradual peripheral vision loss, which may go unnoticed until advanced.
When to Consult an Eye Care Professional
If you experience starbursts around lights, particularly if they appear suddenly or worsen over time, consult an eye care professional. A sudden increase in severity or frequency warrants immediate attention. This is especially true if starbursts are accompanied by eye pain, persistent redness, or vision loss.
Professional evaluation is also important if starbursts significantly interfere with daily activities, such as driving at night. Distorted vision can make it difficult to see streetlights, headlights, and road signs, posing a safety risk. An eye doctor can diagnose the underlying cause and recommend appropriate management or treatment options.